1. Field of the Invention
The present invention generally relates to a device for the coupling of a printing unit, whereby, in a first position, the printing unit, with its plate cylinder, is engaged with a blanket cylinder and, in a second position, the printing unit is disengaged from the blanket cylinder.
2. Background Information
From German Patent No. 41 42 792 A1, there is known a device in which a toggle lever is brought into a stretched position by means of a pneumatic cylinder. In turn, the toggle lever is hinged to a rocker arm, with the plate cylinder being mounted on the rocker arm. This construction allows for the plate cylinder to be brought into two positions, namely, into the position where it is engaged with the blanket cylinder and into a second position where it is disengaged from the blanket cylinder. This system is usually adequate when it is merely for the purpose of engaging plate cylinders with the blanket cylinder before the start of a printing operation and disengaging them again after the end of a printing operation, in order to perform a plate change.
However, there appears to exist the need, in the case of a printing press having a plurality of printing units assigned to one blanket cylinder, to equip the printing press so as to be variable in such a way that the printing press can be optimally operated with a random number of its printing units. The result would be a maximal reduction of material wear and driving power.